基于FPGA的激光雷达回波信号采集卡设计

发布时间：2017-12-28 00:03

本文关键词：基于FPGA的激光雷达回波信号采集卡设计　出处：《中国科学技术大学》2017年硕士论文　论文类型：学位论文

【摘要】：激光雷达是一种主动向目标物发射激光光束,然后通过采集和分析目标物反射的回波信号来得到目标物信息的主动遥感探测设备。回波信号数据采集设备是激光雷达系统的关键部分,为了提高信噪比,回波信号数据采集设备应当具有滤波和高速数据累加功能,为了满足不同重复频率激光雷达的探测需求,累加过程的采集深度和累加次数等参数应当是可配置的。本文使用FPGA作为主控设备,设计了一个采样率为20MHz,具有滤波和硬件累加功能,且参数可配置的通用回波信号采集卡,具体的设计内容如下:1.首先分析了激光雷达回波信号中包括的主要噪声成分及其特性,推导了累加平均法对信噪比的改善程度,并给出了回波信号累加的三种方法。2.接着介绍了采集卡的硬件设计,其中对模拟板卡中的模数转化电路及其外围电路、信号调理电路、电平转换电路、RS232接口电路以及电源电路的设计做了详细的说明,此外还简要说明了数字板卡的结构和功能;3.然后给出FPGA的逻辑设计。这里介绍了 FPGA项目设计的方法与流程、给出了项目的顶层模块设计、分别详细介绍了 FPGA各个功能模块的结构原理和功能仿真的结果,并给出了整个逻辑设计时序仿真的波形图。4.最后对采集卡进行测试,包括对硬件累加功能、信噪比和带宽等性能参数的测试、在激光雷达平台上进行的现场测试以及与Licel的瞬态记录仪的对比测试。测试结果表明,该采集卡实现了基本的参数配置功能和累加功能,其信噪比为71.9dB。与国外某回波信号数据采集设备相比,该采集卡在高重复频率激光雷达中具有更远的探测距离和更高的信噪比。
[Abstract]:Laser radar is a kind of active remote sensing device that actively launches the laser beam to the target, and then obtains the target information by collecting and analyzing the echo signal reflected by the target. Echo signal data acquisition equipment is the key part of the laser radar system, in order to improve the SNR of echo signal, filtering and data acquisition equipment should have high speed data accumulation function, in order to meet the needs of different frequency detection laser radar, sampling depth and cumulative number of parameters such as accumulation process should be configured. This paper uses FPGA as the main control device, designed a sampling rate of 20MHz, with the hardware filter and the accumulation function, and the parameters of general echo signal acquisition card can be configured, the design of specific content as follows: 1. the first analysis of the laser radar echo signal including the main noise components and its characteristics, deduced the cumulative average method to the improvement of the signal-to-noise ratio, and gives three kinds of method of echo signal accumulation. 2. then introduced the hardware design of data acquisition card, the conversion circuit and its peripheral circuit, signal conditioning circuit, voltage conversion circuit, RS232 interface circuit and power circuit design in detail on the board in the simulation module, in addition to a brief description of the structure and function of digital board card; logic design 3. and then FPGA the. This paper introduces the method and process of FPGA project design, gives the top-level module design of the project, introduces the structure principle and functional simulation results of each functional module of FPGA in detail, and gives the waveform diagram of the whole logic design timing simulation. 4., the final collection card is tested, including hardware accumulation function, signal to noise ratio and bandwidth and other performance parameters, on-site testing on the lidar platform and comparison test with Licel transient recorder. The test results show that the acquisition card realizes basic parameter configuration function and accumulative function, and its signal to noise ratio is 71.9dB. Compared with a foreign echo signal acquisition device, the acquisition card has a higher detection distance and a higher signal to noise ratio in the high repetition frequency laser radar.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN958.98;TN791

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